Machine for molding plastic materials



April 18, 1939. J. LAUTERBACH 5 MACHINE FOR MOLDING PLASTIC MATERIALSFiled Aug. 18, 1936 9 Sheets-Sheet 1 gylals 4.412 57%? I April 18, 1939.L T A 2,155,316

MACHINE FOR MOLDING PLASTIC MATERIALS Filed Aug. 18, 1936 9 Sheets-Sheet2 20/ 207 v a M 19 Z April 18, 1939. J. LAUTERBACH MACHINE FOR MOLDINGPLASTIC MATERIALS Filed Aug. 18, 1936 9 Sheets-Sheet I:

J. LAUTERBACH MACHINE FOR MOLDING PLASTIC MATERiALS April 18, 1939. f

Filed Aug. 18, 1936 9 Sheets-Sheet 4 April 18, 1939,. J. LAUTERBACHMACHINE FOR MOLDING PLASTIC MATERI-ALS Filed Aug. 18, 1936 9Sheets-Sheet 5 A ril 18, 1939. J, LAUTERBACH 2,155,315

MACHINE FOR MOLDING PLASTIC MATERIALS Filed Aug. 18, 193 9 Sheets-Sheets April .18, 1939. J. LAUTERBACH 2,155,315

MACHINE FOR MOLDING PLASTIC MATERIALS Filed Aug. 18, 1936 9 Sheets-Sheet7 April 18, 1939.

J. LAUTERBACH 2,155,316

MACHINE FOR MOLDING PLASTIC MATERIALS Filed Aug. 18, 1936 9 Sheets-Sheet8 April 18, 1939. LAUTERBACH 2,155,316

MACHINE FOR MOLDING PLASTIC MATERIALS Filed Aug. 18, 1936 9 Sheets-Sheet9 Patented Apr. 18, 1939 UNITED STATES PATENT OFFICE MACHINE FOR MOLDINGPLASTIC MATERIALS Application August 18, 1936, Serial No. 96,661

8 Claims.

tion Serial Number 3,101, filed January 23, 1935.

A principal object of the invention is to provide an improved moldingmachine of the type wherein a plurality of molding units or dies aremoved progressively and continuously through a predetermined cycle ofoperations, the molding material being fed to the dies at one point inthe cycle, and the finished article being ejected and discharged fromthe machine as the die again approaches that point.

Another object of the invention is to provide a machine of the statedtype wherein actuation of the individual dies is effected by hydraulicmechanism, and to this end, the invention contemplates the provision ofa novel master valve unit through which the aforesaid hydraulic meansand the operation of the dies may be regulated and controlled.

Still another object of the invention is to provide novel andhighlyeflicient means for maintaining the dies during their cyclicoperation at a predetermined temperature, said temperature beingregulated to effect, in conjunction with applied pressure, a proper flowof the molding material in the dies and curing of the molded article.

A further object of the invention is to provide a molding machine of thetype set forth that shall be characterized by,exceptional compactness ofform and simplicity of mechanical structure, and which may be operatedeconomically.

A still further object of the invention is to provide a machine of thestated character that shall be completely automatic in operation.

To this latter end, a further object of the invention is to providenovel and improved means for automatically feeding the moldingcomposition to the dies.

To this same end, a still further object of the invention is to providenovel and efficient means for stripping the molded articles from thedies.

Still another object of the invention is to provide novel means formounting certain of theexterior elements, such as the feeding mechanismso that they may be shifted from the operating to extended positionsaffording free access .to the dies. 6

The invention further resides certain structural features and mechanicaldetails hereinafter described and illustrated in theattached drawings,wherein:

Figure 1 is a front elevational view of a machine made in accordancewith my invention;

Fig. 2 is a plan and partial sectional view of the machine;

Fig. 2a is a fragmentary sectional plan view 5 showing a detail of thedrive mechanism;

Fig. 3 is a section on the line 33, Fig. 2; Fig. 4 is an elevationalView from a position indicated by the line 44, Fig. 2;

Fig. 5 is a fragmentary enlarged sectional view on the line 55, Fig. 1;

Fig. 6 is a fragmentary sectional view on the line 6-6, Fig. 5; I

Fig. 7 is a fragmentary enlarged front elevational view of that portionof the machine illustrated in Fig. 6;

Fig. 8 is an enlarged fragmentary sectional view illustrating details ofthe stripper mechanism;

Fig. 9 is a fragmentary elevational view illustrating details of thecharging mechanism;

Fig. 10 is a section on the line ill-l0, Fig. 9; Fig, 11 is an endelevational view of the mechanism illustrated in Fig. 9;

Fig. 12 is a detached view in perspective of the charging unit;

Fig. 13 is a section on the line i3l3, Fig. 12; Fig. 14 is a verticalsectional view through the master valve unit;

Fig. 15 is a perspective and partial sectional view of one of the valveunits;

Fig. 15a is a detached view of one of the key pins constituting anelement of the valve structure;

Fig. 16 is a section on the line I 6l6, Fig. 15; Fig. 16a is a sectionon the line l6a--l6a, Fig. 15;

Fig. 17 is a view in perspective of another of the valve elements;

Fig. 18 is a section on the line l8'l8, Fig. 17; Fig; 18a is a sectionon the line l8a-l8a, Fig. 17;

Fig. 19 is a sectional View on t1; line Ill -l9, Fig. 1, and

Figs. 20 and 21 are perspective and partial sectional views showing oneform of theflnished product of the machine.

With reference to Figs. 1, 3 and 4 of the drawings, the embodiment ofthe molding machine therein illustrated comprises a base member Isupported upon legs 2. The base member I has at its periphery bosses 3in which are secured vertical tie rods 4 which constitute a support foran upper housing 5. Between the'base I and the housing 5 is a. casing 6which partially through which the said tie embraces the interveningspace and which with the housing 5 forms a chamber for the moving partsof the mechanism. As illustrated, the housing 5 comprises a cover plate1.

Journaled in the central part of the base I is a vertical shaft 8 whichcarries at its lower end a worm wheel 9. To the upper end of this shaftis secured a flange H which carries in the peripheral portion thereof anannular series of hydraulic cylinders |2. As shown in Fig. 3, each ofthese cylinders comprises a main cylindrical section l3 which is closedat the bottom by a threaded plug l4 and which issupported in the flangeII by means of a threaded sleeve l5, this sleeve also receiving athreaded plug l6 which closes the upper end of the cylinder. Each ofthese cylinders is provided at the lower end with a port l1 and towardthe upper end with a port l8, for admission and discharge of anactuating fluid respectively. In each of the cylinders is a hydraulicpiston l9 having a piston rod 2| which extends upwardly through the plugl6, and the usual cup packing 22 is provided at the inner end of theplug l6 to prevent escape of fluid past the piston rod.

Supported on the flange H by means of tie rods 23 is a rotary head ordrum 24, said head having at its lower end an inwardly projecting flange25 rods extend. The flange 25 constitutes a support for a member 26which is secured to the flange 25 by the tie rods 23 and whichconstitutes a support for a shaft section 21 which extends upwardlythrough the head 24 and is journaled at its upper end in anti-frictionbearings in the cover plate 1 of the housing 5. The head 24 alsocomprises a radial flange 28 having a series of vertical bores 29corresponding in number and in vertical alignment with the cylinders l2,and in each of these bores is slidably supported a cylindrical member 3|having at its lower end an extension 32 of reduced diameter which isjoined by means of a suitable sleeve coupling 33 with the piston rod 2|of the aligned hydraulic cylinder l2. Detachably mounted at the upperend of each of the members 3| is a die element 34. The head 24 also hasat its upper end an outwardly projecting radial flange 35 having acircumferential series of cylindrical openings 36 aligned respectivelywith the bores 29 of the underlying flange 28, and each of the openings36 carries a die element 31 designed to cooperate with the aligned dieelement 34 supported as previously described upon the members 3|.

Embracing the shaft 8 immediately below the flange is a master valveunit designated generally by the reference numeral 38. As shown in Figs.3 and 14, this valve unit comprises acentral sleeve 39 which embracesthe shaft 8and which 7 through its lower enlarged portion 4| is securedby means of stud bolts 42 to a plate 43, this plate in turn beingsecured by bolts 44 to the base The bolts 44 pass through concentricarcuate slots in the plate 43, which provides for adjustment in acircumferential direction of the sleeve 39 upon the shaft 8. Embracingthe sleeve 39 is a housing consisting of a lower section 45, which issupported upon the lower extended end 4| of the sleeve and which closelyembraces the latter; a corresponding upper section 46; and anintermediate section- 41, these three sections being secured together bybolts 48. Secured against the upper surface of the upper section 46 ofthis housing is a plate 49 having upwardly projecting pins 5|, whichpins as shown in Fig. 3 enter recesses in the subportion of the flange Hand thereby immobilize the housing 45-46-41 with respect to this flange.Within the space between the intermediate section 41 of the valvehousing and the sleeve 39 is a pair of annular valve elements 52 and 53,each of these elements closely embracing the sleeve 39 and being keyedthereto, as indicated at 54 in Fig. 14. The element 52 rests upon thehousing element 45, and by means of springs 55 interposed between theelements 52 and 53, the latter element' is forced upwardly intoengagement with the under side of the housing element 46. Suitablepacking is provided as indicated at 56 to prevent leakage of fluidbetween the sleeve 39, the housing members 45 and 46 and the valveelements 52 and 53.

It will be apparent from the foregoing description that the sleeve 39being secured to the base I through the medium of the plate 43 remainsstationary, as also do the valve elements 52 and 53 which are secured bythe keys 54 to the sleeve, these keys being in the form of pins (seeFig. 15a) which are threaded into the elements 52 and 53 and projectinto slots 54a in the sleeve 38. The housing 45-4641, however, issecured to the flange II, and through the flange II with the shaft 8with which, therefore, the housing rotates. It will be apparent alsothat the head 24, the die elements supported therein, the pressurecylinders l2 and the housing elements of the master valve 38 rotate withthe shaft 8 as'a unit.

. In the outer faces of each of the valve housing elements 45' and 46 isa series of ports, 51 and 58 respectively, the ports of each seriescorresponding in number with the cylinders I2. The ports 51 of thehousing element 45 are respectively connected through pipes. 59 to theports H of the cylinders l2; and the ports 58 of the housing element 46are similarly connected through pipes 6| with the cylinder ports l8.Each of the ports 51 extends inwardly of the element 45 in the radialdirection and upwardly to the surface contacted by the valve element 52.Each of the ports 58 extends radially inwardly in the housing element 46and downwardly to the surface of that element contacted by the valveelement 53. The lower end surface of the valve element 52, as shown inFig. 1'7, is provided with a flange 62 which extends continuously aroundthe inner periphery of .the valve element with the exception of a narrowradial slot indicated by the reference numeral 63. At each side of thisslot the flange 62 is widened toward the outer periphery of the valveelement, and these widened sections are provided respectively with anelongated port 64 and a circular port 65. The arrangement is such thatas the valve housing 45-46-41 rotates, the ports 51 are broughtconsecutively and successively into communication recessed space 61between the flange 62 and the outer periphery of the valve element. Theport 64 extends upwardly through the body of the valve element 52, seeFig. 18, and communicates at its inner end with an annular recess 66formed in the inner surface of the valve element 52. The port 65 issimilarly connected at its inner end with the recess 66.

The upper end surface of the valve element 53, as shown in Fig. 15,which bears against the valve housing element 46 as previouslydescribed, is provided with an elongated port 68, a transverse slot 69,a port 1|, and a recess 12, with which as the valve. housing rotates theports 58 of the housing element 46 are brought consecutively andsuccessively into communication' As shown in Fig. 16, the port 68communicates with an anelement 53, and the port 1I similarlycommunicates with this recess. The port 68 has a circumferential extentcorresponding with the circumferential extent of the recess 81 of thevalve element 52. The recess 12 of the valve element 53 corresponds inlength with the port 64 of the valve element 52, and the valve elements52 and 53 are so relatively arranged, as shown in Figs. and 17, thatwhen one of the ports 58 is in communication with the recess 12 of theelement 53, the interrelated port 51 is in communication with the port64. A similar positional relation exists between the port 68 of theelement 53 and the recess 61 of the element 52, and between the slot 69and port ll of the element 53 and the port 65 and slot 63 of the element52, respectively. It will be apparent, therefore, that when any one ofthe ports 51 is in communication with the port 64 of the valve element52, its companion port 58, i. e., that one of the ports 58 which isconnected to the same pressure cylinder I3, is in communication with therecess 12 of the valve element 53. Similarly when any one of the ports51 is in communication with the slot 63 of the valve element 52, itscompanion port 58 will be in communication with the port 1| of the valveelement 53. When any one of the ports 51 is in communication with theport 65 of the valve element 52, its companion port 58 will be incommunication with the slot 69 of the valve element 53; and when any oneof the ports 51 is in communication with the recess 61 of the valveelement 52, its companion port 58 will communicate with the port 68 ofthe valve element 53.

As illustrated in Fig. 14, the sleeve 39 is provided with a pair ofports 14 and 15 which extend inwardly from opposite sides of the lowerend of the sleeve respectively. The port v14 extends upwardly throughthe sleeve and communicates at 16 with the space 18 between thev valveelements 52 and 53. The port 15 also extends upwardly through the sleeve39 and communicates at 19 and 8| respectively with the annular recesses66 and 13 of the'valve elements 52 and 53. Thus the port 14 is incontinuous communication with the space 18 between the valve elements 52and 53, and the port 15 is in continuous communication with the annularrecesses 66 and 13 of the said valve elements. Also as shown in Fig. 14,the valve elements 52 and 53 are of lesser diameter than the interiordiameter of thehousing member 41 so that an annular space 82 is formedbetween the valve elements and the housing member which communicateswith the space 18 between the valve elements and also with the recesses61 and 12 of the valve elements 52 and 53 and with the slots 63 and 69of these elements. When, therefore, any one of the ports 51 is incommunication with the slot 63 or recess 61 of the valve element 52,that port 51 is also necessarily in communication with the space 18between the valve elements 52 and 53 and with the port 14. Similarlywhen any one of the ports 58 is in communication with the slot 69 orrecess 12 of the valve element 53, that port is also necessarilyconnected with the space 18 and with the port 14. Since the port 14 isconnected through a pipe 83 with a source of fluid pressure (not shown),it will be apparent that when any one of the ports 51 communicates withthe slot 63 or recess 61 of the valve element 52, fluid pressure will beadmitted to the lower end of the pressure cylinder connected with thatport; and when any one of the ports 58 communicates apparent that whenpressure is admitted to the lower end of any one of the cylinders I3,the upper end of that cylinder will be connected with the port 15, whichthrough a pipe 84 is connected with the exhaust. Under thesecircumstances,

therefore, the fluid pressure entering the lower end of the cylinder I3will force the contained piston I9, upwardly, carrying with it theassociated die element 34. When on the other hand any one of the ports58 is connected with the slot 69 or recess 12 of the valve element 53,the reverse connection between the pressure and exhau'st ports and thecylinder ports 51 and 58 will have been made, with the result that fluidpressure then admitted to the upper end of the cylinder will force thepiston l9 downwardly to the normal depressed position, carrying with itto the normal. depressed position the associated die element 34. In onecomplete revolution of the machine, therefore, the-port 51 of each ofthe cylinders I3, starting for example in communication with the port.64 of the'valve element 52, at which time the piston will be in thedepressed position, will move successively into contact with the slot63, the port 65 and the recess 61. When the port communicates with theslot 63,.pressure is admitted as previously described to the bottom ofthe cylinder so that the piston is forced upwardly. This movement of thepiston, depending on the speed of rotation and the width of the slot 63,may elevate the associated die element 34 to themaximum extentcompletely closing the die, or to a .lesser extent partially closing thedie. Assuming that the closing of the die is completed when the port 51communicates withthe'slot- 63, it will be apparent that when the port 51moves into contact with the port 65 of the valve element 52, there willbe a momentary separation of the die parts, or, in the event that thedie is not completely closed, at least a momentary interruption in theupward movement, permitting the gases to escape from the die and therebyavoiding defects in the moldthe die elements will be completely closed,and' will remain closed with the pressure applied in the bottom of theassociated cylinder I3 during thememaining portion of the rotationalmovement and until the port 51 again is brought into communication withthe port 64, at which time the piston I9 will be forced downwardly inthe cylinder and will open the die. Preferably the ports are sorelatively arranged that the power strokes which respectively close andopen the dies and which occur at opposite sides of the machine will notbe simultaneously initiated.

Means is provided at the beginning of the cyclicfmovement of each die asdescribed above for automatically feeding to the female diemernber 34the, predetermined measured quantity of the molding material required toform the finished product. This device is illustrated in detail in Figs.9 to 13, inclusive, and in Figa 1 and 2. The feeding device is mountedas a unit on a bracket 85 which, as shown in Figs. 2 and 9, is pivotallymounted upon one of the tie rods 4 through the medium of a supportingcollar 86 secured to the tie rod by a set screw 81. The bracket 85comprises upstanding parallel plates 88 and 89 upon the top of which issupported a hopper structure 9|. The hopper structure comprises a baseplate 92 which as shown in Figs. 12 and 13 is mounted in a recess at theupper ends of the plates 88 and 89; and the hopper proper is mountedabove and in spaced relation to the plate 92 by means of lugs 93 whichproject from the sides of the base member 94 of the hopper and seat uponthe extreme upper ends of the said plates 88 and 89. Intermediate thefloor 95 of the hopper and the plate 92 and closely confinedtherebetween is a slide 96. As shown in Fig. 13, the plate 92 is cut outat 91 in the area between the plates 88 and 89, and through this cutoutdepends a' bracket 98 which is secured by bolts 99 to the under side ofthe slide plate 96 and which carries at its lower end a cam roller I8I,this roller fitting in the groove I82 of a cylinder cam I83 which isjournaled, see Fig. 9, in the side plates 88 and 89. Rotation of the camI83 has the effect with the aforedescribed arrangement of longitudinallyreciprocating the slide plate 96 between the base plate 92 and the floor95 'of the hopper.

As shown in Figs. 12 and 13, the said floor 95 has therein an openingI84, and this opening I84 registers, when the slide plate 96 isretracted as shown, with a tapered port I85 in the slide plate 96. Theslide plate 96 comprises an adjustable insert I86 the forward end ofwhich terminates in and forms a part of the wall of the port I85. Therear end of the insert I86 has an upstanding flange I81 which carriesloosely mounted therein for rotation a bolt I88 threaded into anupstanding flange I89 at the rear end of the slide plate 96. Thearrangement is such that through adjustment of the screw I88 theposition of the insert I86 in the slide plate 96 can be varied tothereby vary and to accurately regulate the effective volumetriccapacity of the port I85.

When the feeding device is in the operative position as shown in Fig. 9,the forward edge of the base plate 92 occupies a position of alignmentwith the cavities 34a of the female die elements 34 as the latter movein their circular path, the said forward edge of the base plate 92beingprovided with an arcuaterecess III which conforms to thecircumference of the cavity 34a. Assuming that the hopper 9| contains acomminuted molding composition, it will be apparent that when the slideplate 96 is retracted as shown in Fig. 12, this material will fall bygravity into and will fill the port I85 .of the plate, and that when theslide plate 96 is subsequently advanced, the measured quantity of thismaterial filling the port I 85 will be carried out of the hopper andwill eventually be deposited in the cavity 34a of one of the dies 34 bymovement of the port I85 of the plate 96 beyond the terminal edge of thebase plate 92 and into a position directly above the said cavity.

As shown in Fig. 9, the cylinder cam I83 has trunnions H2 and H3journaled respectively in the plates 88 and 89. Secured to the outer endof the trunnion H3 is a disk H4 having therein an aperture in which isloosely mounted a pin H5. A leaf spring H6 engages the outer end of thepin H5 and urges it resiliently inwardly. At the out r side of the diskH4 and pivotally mounted 'thereon'in-concentric position is a pinretractor cam H1 having a. slot I I8 for reception of the pin that whenby reason of relative movement between the disk H4 and the cam. II1 thebin H5 moves into the slot H8, these inclined surfaces H9 will have theeffect of retracting the pin against the tension of the spring H6 to. aposition as shown in Fig. 9. The cam H1 is urged away from thepin-engaging position by means of a spring-pressed pin I2I supported ina keeper I22 secured to the face of the disk H4, and this keeper'alsotends by cooperation with the surfaces. I23 and I24 of the cam element II1 to limit the movement of this cam element with respect to the diskH4.

Loosely mounted upon the trunnion I I3 of the cylinder cam I83 is a gearI25 having a hub portion I26 containing in its outer face an apertureI21 adapted for reception of the pin H5. When the pin is advanced by thespring I I6 and enters the aperture I21, the gear I25 will thereby heimmobilized with respect to the trunnion H3. Journaled in the plates 88and 89 of the the lower portion of the plate 89 is a rod I39 theupperend of which, as shown in Figs. 9 and 11, normally occupies aposition in the path of the cam element H1. When so positioned, the rodI39 prevents rotation of thecam H1 with the disk H4. Assuming underthese conditions that the pin I I5 is advanced and engaged in theaperture I21 of the gear hub I26 and that the gear I25 is being drivenfrom the motor I34 by the interconnecting elements, it will be apparentthat when the cam H1 engages the upper end of the rod I39 as shown inFig. 11 the continued rotation of the disk I I4 will effect through theaction of the cam surfaces H9 a retraction of the pin I I5,disconnecting the gear I25 from the trunand tends to hold the rod in theoperative position,

as shown in the drawings. Adapted to operate against the rod I39 at apoint below the pivot but on the same side as the pin MI is a core rodI42 of a solenoid I43. The rear end of the rod I42 is engaged by acoiled spring I44 the other end of which is suitably connected with thebracket, and this spring normally holds the plunger rod I42 in aretracted position, as shown in Fig. 9, this position being det mined bya collar I45 secured to the rod whic engages the forward face of a stopplate I46. The rod I42 thereby constitutes a stop for the lower end ofthe rod I39, against which the latter rod bears when in the normalposition as illustrated. When the solenoid is energized, the plunger rodI42 is projected suflioiently to swing the rod I39 around its pivot I31to an extent clearing the upper edge of the 'rod from the cam H1. Whenthe cam I "is released in this manner from the rod I39, the cam isshifted in a clockwise direction, as seen inFig. 11, by means of thespringto an extent permitting the pin I I to'enter the recess I21 in thehub portion I26. The gear I25 then carries the disk H4 and with it thecylinder cam- I03 through one complete revolution, at the end of whichthe rod I39, which in the meantime has been released by deenergizationof the solenoid I43 and has been moved by the spn'ngpin I4I to thenormal operative position,

by reengagement with the cam II1 causes the latter to withdraw the pinII 5 from the recess I21. In this movement, the cylinder cam I03 hasalso moved through one complete revolution, and in order to prevent abackward movement of this cam by action of the spring-pressed pin I21, Iprovide a latch I41 the hooked end of which is adapted to engage a bossI48 projecting from the cylindrical surface of the cam, as shown in Fig.10,,this latch being'resiliently held in the operative position, asshown, by means of a spring I49.

The timing of this feeding device is synchronized with. therotationalmovement of the die block or head 24, so that as each one of the dies 34moves into aligned position with the base plate 92, the slide plate 96will be advanced to an extent depositing the predetermined measuredquantity of the molding material withdrawn from the hopper as describedinto the die. In this connection, attention is directed to the form ofthe cam slot I02, as shown in Fig. 9. In one revolution of this cam,thefeed plate 96 is fully advanced to a position in which the openingI05 overlies the cavity 34a of the female die. It is then'retracted to asmall extent and again advanced to the extreme position by means of ajogging action effected by the notch in the cam slot I02 indicated inFig. 9 at Ma. This gives a jogging movement to the feed plate 96 at theforward end of its stroke, dislodging all of the molding material whichmight otherwise .tend to adhere to the walls of the port I05 andinsuring an accurate deposition of the exactly measured quantity of thematerial in the cavity 340..

It will be noted that by reason of the pivotal mounting of the bracket85 as described above, the entire feed unit may be swung away from thenormal operative position in which it is shown and toward the right asviewed in Fig. 2, thereby affording access to the interior of thehousing 5 at that point.

By reference to Fig. 3, it will be noted that each of the male dieelements 31 is provided with a longitudinal bore in which is slidablymounted a pin I5I. In the normal elevated position of this pin shown atthe right of Fig. 3, the lower end thereof forms a part of the efiectivebottom surface of the male die element. In a depressed position of thepin I5I, as shown at the left in Fig. 3, this pin projects below thebottom normal surface of the male die element and constitutes an ejectorfor dislodging the molded article which.

adheres to the relatively fixed male die when the female die element 34has been retracted to its normal depressed position. The pin.I5I issecured at its upper end to a cross bar I52, which bar is secured at theupper end of a rod I53. The rod I53 extends downwardly through the dieblock 24 and carries at its lower end an arm I54 which extendstransversely and loosely embraces the rod 32.

I52 tending to hold the rod I53 in an elevated position determined by anadjustable stop sleeve I56 on the rod I53, this sleeve in the elevatedposition of the rod engaging the under side of the die block 24. Whenthe pistons I9 are elevated A spring I55 exerts pressure on the arm intheir cylinders, the rod I53 ismermitted by action of the spring I 55 toassume its normal elevated position. When the pistons I9 are moveddownwardly in theircylinders to lower the female dies 34, the members 3Iengage the arms I 54 and move the rods I53 downwardly as shown at theleft in Fig. 3, thereby depressing the ejector pin I5I. This type ofejector is adaptable for molded articles of the character for exampleshown in Fig. 21.

For articles of the character shown in Fig. 20, having internal threads,a different character of ejector or stripping device is employed, adevice of this character being illustrated in Figs. 1 and 2, and 4 to 8,inclusive. In this instance, it is necessary to unthread the moldedarticle from the threaded male die to which it adheres when the femaledie 34 is lowered. To this end, I provide an arm I51, see Fig. 8, whichis pivotally mounted at I58 to the side of the housing 5 for horizontalmovement. The free end of the arm I 51 turns inwardly through an openingI59 in the front of the housing 5 and carries a fingered pawl I6I whichis pivotally secured at I62 to the inner end of the arm, a spring I63urging this pawl in one direction about the pivot. Pivotal movement ofthe pawl I6I under the actuation of the spring I63 is limited by a stopplate I64. The arm I51 is urged inwardly toward the housing 5 by aspring I65, and the inner position of the arm is determined by a setscrew I66. The normal position of the arm I51 and pawl I6I is shown inFig. 5, wherein it will be noted that the pawl lies directly in the pathof the male die element and of the molded article which adheres theretoas previously described. As the die moves in its rotary path, the sideof the molded article is engaged by the inner finger of the pawl I6I asillustrated, and the continued movement of .the die has the effect ofswinging the pawl so that the outer finger is brought inwardly againstthe side of the molded article. It is preferable to form the moldedarticle with ribs or recesses on its outer surface that will provide abearing for the fingers of the pawl I6I so that the latter may in effectgrip the article. Still further advance movement of the dies causes amovement of the pawl I6I and of the arm I51 toward the position shown inFig. 8, and in this movement the molded article is given a clockwiserotation, as viewed in- Figs. 5 and 8, by the action of the pawl,thereby loosening the" molded article on the threads of the male dieelement.

As the die advances further in its rotary path and frees the moldedarticle from the pawl I6 I, the said article is engaged by a rotary diskI61 which is rotated at a relatively rapid rate in the directionindicated by the arrow in Fig. 5. The peripheral portion of the disk I61is made of a flexible material, such for example as felt or rubber, and

has the effect of rotating the already loosened molded article on thethreaded male die to an extent stripping the article from the die. Thedisk I61 is carried at the lower end of a vertical shaft I68, see Fig.1, which is supported in bearings in a bracket I69 which is pivotallymounted upon a pintle I supported in a bracket I12 secured to thehousing 5, see Fig. 4. This bracket also carries an electric motor I13which is connected to a shaft (not shown) extending through andjournaled in a cylindrical housing I14. This latter shaft is connectedby means of a worm and worm wheel (not shown) to the shaft I69, themotor I13 thereby constituting the means for rotating the disk I 61.

Directly below the disk I61 is a chute I15 which is mounted on a bracketI16 pivotally supported upon one of the tie rods 4 by means of a collarI11, see Fig. 1. As shown in Fig. 6, the chute I15 extends upwardly andinwardlyto a point below and in back of the line of travel of the diesso that when the molded article is stripped from the male die, the saidarticle will fall by gravity into the chute to be discharged to theoutside of the machine. In order to insure a prompt discharge of themolded article from the chute, I provide at the upper end of the lattera tube I18 which is connected to a source of-air pressure and which hasapertures I18 through which an air blast may be directed downwardly ofthe chute. The tube I18 extends downwardly to the bottom of the bracketI16 and is connected through a flexible tube I8I, see Fig. 4, with avalve I82, which valve is supported in the present instance upon a crossbar I83 extending between and secured to two of the tie rods 4. From thevalve I82 a tube I84 extends downwardly and is connected with a tube I85extending to the source of air pressure. The lower end of the tube I84is provided with a drain cock I86. The valve I82 is normally closed andis opened to admit compressed air to the tube I8I through the medium ofa lever I81 which is pivotally mounted at I88 and projects inwardly intothe path of an annular series of vertical rods I88 which constituteguides for the die-supporting members 3|. see Figs. 2 and 3. As thereinillustrated, each of the members 3I has a flange I8I extendingtransversely from the lower end thereof and notched at its outer end forsliding engagement with one of the rods I88. These rods are secured toand extend vertically between the plate II and the die block 24, andfunction to prevent rotary movement of the die-supporting members 3|. Aseach of the rods I88 in their rotary movement with the die block 24engages the inner end of the lever I81, the latter is swung on its pivotin a counterclockwise direction, as viewed in Fig. 2, with the resultthat a set screw I82 in the outer end of an arm I 83secured to the armI81, see Fig. 2, presses the valve stem I 820 which it engages inwardly,thereby opening the valve. This periodic opening of the valve is intimed relation with the stripping action which deposits the moldedarticles in the chute I15, as previously described, and the effect ofthe blast of air passing from the ports I18 of the tube I18 is to forcethe molded article downwardly in the chute so that it may fall bygravity from the lower end of the latter. The bracket I16 which carriesthe chute I15 also supports a suction hood I84 the open side of whichcommunicates with the upper end of the chute I15. This hood I84 isconnected through a suitable duct I85 with a source of suction (notshown), which operates to withdraw the flashings removed from the moldedarticle by the action of the disk' I81. It will be noted that thislatter function of the disk I61 leaves the molded article in a clean andfinished condition so that no further operation is required after themolded article has left the machine. a

The shaft 8 is rotated by an. electric motor I85 which as shown in Figs.2 and 4 is mounted upon a bracket I 86 supported at the back ofthemachine upon two of the tie rods 4. This motor is connected throughbelts I81 and I88 and pulleys I88, 28I, 282 and 283 with a shaft 284 atthe bottom of the machine. tachably connected with the shaft 284 througha clutch 285. The shaft 284 carries a worm located ter are in theelevated position.

The pulley 283 is de-' in a housing 286 which meshes with a worm wheelon a shaft 281, this shaft being connected through a suitable coupling288 with a shaft 288 which carries a worm 2 I I meshing with the wormwheel 8 at the bottom of the shaft 8. The clutch 285 is controlled by aclutch rod 2 I 2 which is pivotally mounted at 2 I3 and extendsupwardly, and has-pivotally secured to-its upper end a link 2I4. Theouter end of this link is adapted to engage in a suitably formed notchin a block 2I5 secured to the base I, as shown in Fig. 4, and when soengaged retains the clutch rod 2I2 in the clutchengaging position asillustrated against the ten-' sion of a coiled'spring 2I6 which exertspressure tending to draw the clutch rod 2I2 into a position releasingthe clutch 285 and thereby disconnecting the shaft 284 from the motorI85. Toward its outer end, the link 2I4 is engaged at the top by a pin2I1 which is carried at the lower end of a slide rod 2I8 supported forvertical movement on the base I and housing 5. A spring 2I8 exertspressure on the rod 2I8 tending to draw this rod downwardly, but isnormally prevented by a bar 22I which is slidably supported forhorizontal movement on the housing 5 and one end of which engages andsupports the hooked upper end 2 I 8aof the rod 2 I8, as shown in Fig. 4.When the slide bar 22 I is moved to the right, as viewed in Fig. 4, toan extent releasing the hooked end 2I8a of the rod 2I8, the spring 2I8draws this rod downwardly, thereby depressing the outer end of the link2I4 and clearing this link from the stop block 2I5. The

spring 2I6 then is permitted to draw the clutch rod 2| 2 to the right,see Fig. 4, to disengage the clutch 285. The slide bar MI is normallyinterlocked as'indicated at 222 in Fig. 4 with a bar 223 which isslidably supported on the housing 5 and which as shown in Figs. 2, 5 and'1 extends around the side of the housing 5 and has an inturned endportion 224 which extends into the interior of the housing below the rodI51, the inner end of the rod 224 carrying a block 225 which occupies aposition directly below the path of travel of the male dies 31 anddirectly in the path of thefemale die elements 34 when the latapproachthe stripping position, the female die elements 34 have been carrieddownwardly to their depressed position, as shown in Fig. '1, so that asthe die block rotates, these female elements 34 pass under the stopblock 225. If, however, the female elements by reason of a defect in theoperating mechanism have failed to move to the retracted or depressedposition at this point, they will engage the stop block 225 and willforce the bar 223 to the right, as viewed in Figs. 4, 5 and '1, with theresult that the bar MI is also moved to the right sufficiently torelease the rod 2I8 as previously described and to thereby disconnectthe motor I85 from the shaft 284, interrupting the movement of the dieblock. This automatically operating safety device prevents the damagethat would otherwise occur, as for example by engagement of the femaledie elements with the upper end of the trough I15, were these female dieelements not fully retracted as they move into the stripping position.It will be apparent that the operation of the machine may inders I2 andthe movable-elements of the valve As the dies 38 will rotatecontinuously and at a predetertwo of the tie rods 4 and carries a plate22'! upon which is mounted a pair of electrical contacts or switchelements 228 and 229. The contact 228 is slidably mounted in a suitablebearing block 23I and is urged into an advanced position by means of aspring 232. The contact 229 is similarly slidably mounted in a block233, and a spring 234 normally retains this contact in a retractedposition and separated from the contact 228, all as shown in Fig. 2. Apivoted lever 235 on the plate engages the end of the contact 229, andin turn is engaged by asecond lever 2 36 which is pivotallysecured at231 on the plate 221. A spring 238 tends to hold the outer end ofthelever 236 against the free end of the lever 235, and the inner end ofthe lever 236 lies in the path of the series of rods I89. As the dieblock rotates and with it the rods I89, the latter successively engagethe lever 236- and swing the outer -end of the lever away from the lever235. When the inner end of the lever 236 is re leased by the rod I89,the spring 238 acts to swing the outer end of the lever 236 sharplyagainst the lever 235, which drives the contact 229 inwardly against thecontact 228, thereby closing the electric circuit of which thesecontacts form a part. This electric circuit includes, in addition to asource of electrical energy, the solenoid I43, .so that when the circuitis closed as described, the solenoid is energized, thereby forcing therod I42 outwardly and oscillating the lever I39 to an extent freeing thecam I". When thus freed, the cam is moved away from the pin II5, whichis thereby permitted to enter the recess I21 in the hub I26 of the gearI25, connecting the cylinder cam I63 with the motor I34 as previouslydescribed. Since after energization the solenoid I43 is immediatelydeenergized through separation by the spring 234 of the contacts 228 and229, the stop bar I39 is immediately permitted to return under operationof the spring-pressed pin I H to a position'in the path of the cam I",so that after one complete revolution of the cylinder cam I93,- the camI I1 functions again to retract the pin I I5 and thereby brings thecylinder cam I03 to a standstill. One complete revolution of thecylinder cam I93 causes a projection of the slide plate 96 of thecharging mechanism and a retraction of this plate to its originalposition, as shown in- Figs. 12 and 13, the-advanced position of thisplate being indicated in these figures in broken lines. Since theintermittent actuation of the charging device is controlled by therotary movement of the block 24 and associated parts connected with theshaft 8, it will be apparent that the actuation of the charging-devicemay be accurately synchronized with the movement of' the dies to effectan accurate charging of the latter.

The elevation and retraction of the die elements 34 controlled by themaster valve 38 as previously described maybe further regulated as tothe speed of the elevating and retractive movements through the mediumof a needle valve shown in Fig. 19, which is connected in the pipe 83through which the motivating fluid is conducted to the cylinders I2.This valve comprises a manually adjustable valve element 239 by means ofwhich the flow of fluid to themaster valve 38 from the source maybecontrolled and accurately regulated. A similar valve (not shown) may beplaced in the discharge line 84 to regulate and control the piston speedby back pressure on the discharge. The timing of the die actuation withregard to the cyclic movement may be regulated by adjustment of theplate 43 about the axis of the shaft 8, for which adjustment provisionis made as previously set forth in the slotted openings for the bolts44. It will be apparent that adjustment of the plate 43 as describedwill also effect an angular adjustment. of the relatively fixed elementsof the master valve 38 comprising the sleeve 39 and the valve elements52 and 53.

Means is also provided as illustrated in Fig. 3 for electrically heatingthe dies and for maintaining them at a proper temperature for themolding operation. This device comprises a pair of contact elements 24Iand 242 which are connected to the heating circuit and which extendthrough the cover I of the housing 5 to respec tively contact themetallic rings 243 and 24.4 mounted at the top of the die block 24. Fromthese rings, wires pass to heating elements 245 'ments over apredetermined cyclic path. means for'relatively moving the die elementsin synchronism with the movement of the block to periodically bringtogether and separate said elements, and means operative automaticallyand intermittently to charge the female die at a given position in itscyclic path with a measured quantity of a molding composition, saidmeans in operative position projecting through an opening in saidhousing and being formed as a unit comprising a hopper, means fortransferring the said composition from the hopper to the die, mechanismfor actuating said transfer means, and a bracket forming a commonsupport for said hopper, transfer means and actuating mechanism, meanson said frame forming a vertical pivot support for said bracket uponwhich said bracket may be swung horizontally between the said operativeposition and a retracted position affording access both to the saidcharging mechanism and, through said housing opening, to the dies, andmeans for releasably locking said charging unit in the operativeposition. 1

2. In a molding machine, the combination with a mobile die block, ofrelatively movable coacting male and female die elements carried by saidblock, means for effecting a continuous movement of said block carryingthe die elements over a predetermined cyclic path, means for relativelymoving the dieelements in synchronism with the movement of the block toperiodically bring together and separate said elements, means operativeintermittently and in synchronism with said last-named means fordepositing in-the female die element at a given position in its cyclicpath a measured quantity of a molding composition, said male elementbeing formed so that an article molded between the die elements willadhere to the male element when the elements are separated, means forautomatically stripping the molded article from the male die element atanother position in said path, said stripping means comprising a rotaryelement positioned with its periphery adjacent the path of said maleelement so as to engage a molded article adhering to the latter elementand to effect a rotary movement of said article with respect to the maleelement, and means operative upon the molded article in advance of saidrotary element for twisting and thereby loosening the molded articlewith respect to and on the male die element.

3. In a molding machine, the combination with a mobile die block, ofrelatively movable coacting male and female die elements carried by saidblock, means for effecting a continuous movement of said block carryingthe die elements over a predetermined cyclic path, means for relativelymoving the die elements in synchronism with the movement of the block toperiodically bring together and separate said elements, means operativeintermittently and in synchronism with said last-named means fordepositing in the female die element at a given position in its cyclicpath a measured quantity of a molding composition, said male elementbeing formed so that an article molded between the die elements willadhere to the male element when the elements are separated, and meansfor automatically stripping the molded article fromthe male die elementat an-; other position in said path, said stripping means comprising arotary element positioned with its periphery adjacent the path of saidmale element so as to engage a molded article adhering to the latterelement and to efiect a rotary movement of said article with respect tothe male element, and means operative upon the molded article in advanceof said rotary element for twisting and thereby loosening the moldedarticle with respect to and on the male die element, said lastnamedmeans comprising a pawl located normally in the path of said male dieelement for engagement with the molded article carried by the latter andbeing resiliently mounted for displacement from said path by contactwith the molded article as the latter advances with the die, and meanswhereby said displacement'efiects a rotary move- -"ment of the pawlturning themolded "article on the die.

4. In a molding machine, the combination with a mobile die block, ofrelatively movable coacting male and female die elements carried by saidblock, means for effecting a continuous movement of said block carryingthe die elements over a predetermined cyclic path, means for relativelymoving the die elements in synchronism with the movement of the block toperiodically bring to gether and separate-said elements, means operativeintermittentlyand in synchronism with said last-named means fordepositing in the female die element. at a given position in its cyclicpath a measured quantity of a molding composition, said male elementbeing formed so that an article molded between the die elements willadhere to the male element when said elements are separated, and meansfor automatically stripping the molded article from the male die elementat another position in said path, said stripping means comprising arotary element positioned with its periphery adjacent the path of saidmale element so as to engage a molded article adhering to the latterelement and to effect a rotary movement of said article with respect tothe male element, and means operative upon the molded article in advanceof said rotary element for twisting and thereby loosening the moldedarticle with respect to and on the male die element, said last-namedmeans comprising an arm resiliently mounted for movement toward and fromthe path of said male die element, a pawl element pivotally mounted onsaid arm and projecting into the path of said male die element andadapted to enage the molded article carried thereby, resilient meanstending to hold the pawl in the path of' said molded article, said pawlbeing adapted to be turned on its pivot against the pressure of saidspring by movement of the molded article with the die and to therebyexert upon said article a turning force loosening the article on thedie.

5. In a molding machine, the combination with a mobile die block, ofrelatively movable coacting male and female die elements carried by saidblock, means for efiecting a continuous movement of said block carryingthe die elements over a predetermined cyclic path, means for relativelymoving the die elements in synchronism with the movement of the block toperiodically bring together and separate said elements, means operativeautomatically and intermittently to deposit a predetermined measuredquantity of a molding composition in the female die at a given positionin its cyclic path, said male die element being formed so that anarticle molded between the die elements will adhere to the male elementwhen the elements are separated, and means for automatically strippingthe molded article from the male die element at another position in saidpath, said. means comprising a rotary element mounted with its peripheryadjoining the path of the male die element for engagement with a moldedarticle adhering to the latter, and means for rapidly rotating saidelement in frictional contact to be retracted to a relatively depressedposition, a chute projecting into the space below the path of said maleelements for reception of molded articles stripped from the latter,saidchute lying inthe path of said female elements when the latter are inthe elevated position but above the path of said female elements whenthe latter are depressed, motor means for effecting a continuousmovement of said block carrying the die elements over a predeterminedcyclic path, means operative in synchronism with the movement of theblock for elevating and depressing the female die element and operativenormally to move said female element to the depressed position'as itapproaches said chute, and means positioned in advance of said chute andoperative by engagement thereof with the female element for interruptingdie elements carried by said block, said female element being adapted tobe elevated into coactive position with respect to said male elementandto be retracted to a relatively depressed position, a 5 chute projectinginto the space below the path oi.

said male elements for reception of molded articles stripped from thelatter, said chute lying in the path of said female elements when thelatter are in the elevated position but above the path 10 pressed, motormeans for effecting a continuous movement of said block carrying the dieelements over a'predetermined cyclic path, means operative insynchronism with the movement of the block :15 for elevating anddepressing the female die elemeut and operative normally to move saidfemale element to the depressed position as it approaches said chute,and means positioned in advance of said chute and operative byengagement thereof is) with the female element for interrupting themovement of said die block in the event that the female element inapproaching the chutefails to move to the depressed position, saidinterrupting means comprising a clutch normally connecting the blockwith said driving means, and a clutchtive when engaged of said femaleelements-when the latter are de-- thelatter.

actuating element positioned in the path of the female die when thelatter is in the elevated position but above the path of the female diewhen the latter is in the depressed position and operaby said female dieto release said clutch. i i

8. In a molding machine, the combination with a mobile die block, of aplurality of sets of relatively movable coacting'male and female dieelements carried by said block, means for effecting a movement of saidblock carrying the die elements over a predetermined cyclic path, anhydraulic mechanism for relatively moving the die elements of each setto close and subsequently open the die. and a master valve operating insynchronism with the movement of the die block to actuate saidmechanisms at predetermined positions in said cyclic path, said valvecomprising means for momentarily interrupting the flow o1 actuatingfluid to the respective mechanisms in the closing movement of saidelements to permit the escape of gases from molding composition confinedin said die prior to the final closing or Jonu mu'manacn.

